grpcxx

🚀 Blazing fast gRPC C++ Server implemented using modern standards (C++20).

Features

• Fast - More than 2x faster compared to the official implementation(s).
• Simple - Overall smaller codebase and 95% less generated code compared to the official implementation.
• Flexible - The application code is given greater implementation choice by using C++ concepts instead of being restricted to one choice.

Benchmarks

You can find more detailed benchmark results in #25 and #21 (comment).

	1a	1b	2a	2b	3a	3b
gRPC v1.48.4 (callback)	25k	87k	76k	152k	96k	142k
grpc-go v1.56.2	27k	103k	94k	191k	90k	308k
Rust (tonic v0.10.2)	29k	66k	95k	176k	68k	212k
grpcxx v0.2.0 (single-threaded)	42k	193k	120k	449k	160k	452k
grpcxx v0.2.0 (2 workers)	33k	166k	120k	431k	91k	425k
grpcxx v0.2.0 (hardware concurrency)	34k	164k	118k	450k	101k	408k

Documentation

You can find a bit more detailed documentation in docs/.

Getting started

Prerequisites

• CMake (>= 3.23)
• Protobuf (>= 3.15)

Installing

There aren't any installable packages at this stage but you can add this to your CMake project as a dependency using FetchContent.

e.g.

# grpcxx
FetchContent_Declare(grpcxx
  URL      https://github.com/uatuko/grpcxx/archive/refs/tags/v0.1.3.tar.gz
  URL_HASH SHA256=441ca21bed3c0413623440c1608da44e60931631af1dc609c18e4a955f8cb3a5
)
FetchContent_MakeAvailable(grpcxx)

Using grpcxx

💡 You can find a complete helloworld example here.

In order to use grpcxx (similar to other gRPC implementations) you'll need to;

1. Generate code
2. Implement RPC endpoints
3. Run a server to process RPC requests

Code generation

You can use the protoc-gen-grpcxx Protobuf compiler plugin to generate the Protobuf and gRPC server code.

e.g.

❯ protoc --proto_path=. \
  --cpp_out=/path/to/output \
  --grpcxx_out=/path/to/output \
  --plugin=/path/to/protoc-gen-grpcxx \
  helloworld/v1/greeter.proto

This will generate 3 files, which you'll need to compile and include in your build.

❯ tree /path/to/output
/path/to/output
└── helloworld
  └── v1
    ├── greeter.grpcxx.pb.h
    ├── greeter.pb.cc
    └── greeter.pb.h

Implementing RPC endpoints

Code generation only creates a stub service to return UNIMPLEMENTED gRPC status responses for all the endpoints. You will need to add your own implementation to return something more meaningful.

One way to do this is by specialising the generated ServiceImpl struct.

e.g.

#include "helloworld/v1/greeter.grpcxx.pb.h"

using namespace helloworld::v1::Greeter;

// Implement rpc application logic using template specialisation for generated `ServiceImpl` struct
template <>
rpcHello::result_type ServiceImpl::call<rpcHello>(
  grpcxx::context &, const GreeterHelloRequest &req) {
  GreeterHelloResponse res;
  res.set_message("Hello `" + req.name() + "` 👋");
  return {grpcxx::status::code_t::ok, res};
}

💡 The generated ServiceImpl struct is a very simple struct with 6 lines of code. You can easily create your own instead of having to use the generated code giving you more flexibility to structure your code in a way that works best for you. An example of this can be found here.

Running a server

e.g.

helloworld::v1::Greeter::ServiceImpl greeter; // Instance of the RPC implementation
helloworld::v1::Greeter::Service     service(greeter); // Service (using the RPC implementation)

grpcxx::server server; // Server instance
server.add(service); // Add the service to the server instance

std::printf("Listening on [127.0.0.1:7000] ...\n");
server.run("127.0.0.1", 7000); // Listen and serve